Lab- Configuring Basic Single-Area OSPFv2

Transcription

1 Lab- onfiguring Basic Single-Area OSPFv2 Topology G0/0 G0/ isco and/or its affiliates. All rights reserved. This document is isco Public. Page 1 of 29

2 Addressing Table Objectives Device Interface IP Address Subnet Mask Default Gateway R1 G0/ N/A S0/0/0 (DE) N/A S0/0/ N/A R2 G0/ N/A S0/0/ N/A S0/0/1 (DE) N/A R3 G0/ N/A S0/0/0 (DE) N/A S0/0/ N/A P-A NI P-B NI P- NI Part 1: Build the Network and onfigure Basic Device Settings Part 2: onfigure and Verify OSPF Routing Part 3: hange Router ID Assignments Part 4: onfigure OSPF Passive Interfaces Part 1: Build the Network and onfigure Basic Device Settings In Part 1, you set up the network topology and configure basic settings on the P hosts and routers. Step 1: able the network as shown in the topology. Step 2: Initialize and reload the routers as necessary. Step 3: onfigure basic settings for each router. a. Disable DNS lookup. b. onfigure device name as shown in the topology. c. Assign class as the privileged EXE password. d. Assign cisco as the console and vty passwords. e. onfigure a message of the day (MOTD) banner to warn users that unauthorized access is prohibited. f. onfigure logging synchronous for the console line. g. onfigure the IP address listed in the Addressing Table for all interfaces. h. Set the clock rate for all DE serial interfaces at i. opy the running configuration to the startup configuration isco and/or its affiliates. All rights reserved. This document is isco Public. Page 2 of 29

3 Step 4: onfigure P hosts. Step 5: Test connectivity. The routers should be able to ping one another, and each P should be able to ping its default gateway. The Ps are unable to ping other Ps until OSPF routing is configured. Verify and troubleshoot if necessary. Part 2: onfigure and Verify OSPF Routing In Part 2, you will configure OSPFv2 routing on all routers in the network and then verify that routing tables are updated correctly. After OSPF has been verified, you will configure OSPF authentication on the links for added security. Step 1: onfigure OSPF on R1. a. Use the router ospf command in global configuration mode to enable OSPF on R1. R1(config)# router ospf 1 Note: The OSPF process id is kept locally and has no meaning to other routers on the network. b. onfigure the network statements for the networks on R1. Use an area ID of 0. R1(config-router)# network area isco and/or its affiliates. All rights reserved. This document is isco Public. Page 3 of 29

4 R1(config-router)# network area 0 R1(config-router)# network area 0 Step 2: onfigure OSPF on R2 and R3. Use the router ospf command and add the network statements for the networks on R2 and R3. Neighbor adjacency messages display on R1 when OSPF routing is configured on R2 and R3. R1# 00:22:29: %OSPF-5-ADJHG: Process 1, Nbr on Serial0/0/0 from LOADING to FULL, Loading Done R1# 00:23:14: %OSPF-5-ADJHG: Process 1, Nbr on Serial0/0/1 from LOADING to FULL, Loading Done R1# Step 3: Verify OSPF neighbors and routing information. a. Issue the show ip ospf neighbor command to verify that each router lists the other routers in the network as neighbors. R1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface FULL/ - 00:00: Serial0/0/ FULL/ - 00:00: Serial0/0/0 b. Issue the show ip route command to verify that all networks display in the routing table on all routers. R1# show ip route odes: L - local, - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is not set L O O L L O /24 is variably subnetted, 2 subnets, 2 masks /24 is directly connected, GigabitEthernet0/ /32 is directly connected, GigabitEthernet0/ /24 [110/65] via , 00:32:33, Serial0/0/ /24 [110/65] via , 00:31:48, Serial0/0/ /24 is variably subnetted, 2 subnets, 2 masks /30 is directly connected, Serial0/0/ /32 is directly connected, Serial0/0/ /24 is variably subnetted, 2 subnets, 2 masks /30 is directly connected, Serial0/0/ /32 is directly connected, Serial0/0/ /30 is subnetted, 1 subnets /30 [110/128] via , 00:31:38, Serial0/0/0 [110/128] via , 00:31:38, Serial0/0/ isco and/or its affiliates. All rights reserved. This document is isco Public. Page 4 of 29

5 What command would you use to only see the OSPF routes in the routing table? show ip route ospf Step 4: Verify OSPF protocol settings. The show ip protocols command is a quick way to verify vital OSPF configuration information. This information includes the OSPF process ID, the router ID, networks the router is advertising, the neighbors the router is receiving updates from, and the default administrative distance, which is 110 for OSPF. R1# show ip protocols *** IP Routing is NSF aware *** Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: area area area 0 Routing Information Sources: Gateway Distance Last Update :19: :20:03 Distance: (default is 110) Step 5: Verify OSPF process information. Use the show ip ospf command to examine the OSPF process ID and router ID. This command displays the OSPF area information, as well as the last time the SPF algorithm was calculated. R1# show ip ospf Routing Process "ospf 1" with ID Start time: 00:20:23.260, Time elapsed: 00:25: Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Supports NSSA (compatible with RF 3101) Event-log enabled, Maximum number of events: 1000, Mode: cyclic Router is not originating router-lsas with maximum metric Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs msecs Maximum wait time between two consecutive SPFs msecs Incremental-SPF disabled Minimum LSA interval 5 secs Minimum LSA arrival 1000 msecs LSA group pacing timer 240 secs 2013 isco and/or its affiliates. All rights reserved. This document is isco Public. Page 5 of 29

6 Interface flood pacing timer 33 msecs Retransmission pacing timer 66 msecs Number of external LSA 0. hecksum Sum 0x Number of opaque AS LSA 0. hecksum Sum 0x Number of Dbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Number of areas transit capable is 0 External flood list length 0 IETF NSF helper support enabled isco NSF helper support enabled Reference bandwidth unit is 100 mbps Area BAKBONE(0) Number of interfaces in this area is 3 Area has no authentication SPF algorithm last executed 00:22: ago SPF algorithm executed 7 times Area ranges are Number of LSA 3. hecksum Sum 0x019A61 Number of opaque link LSA 0. hecksum Sum 0x Number of Dbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0 Step 6: Verify OSPF interface settings. a. Issue the show ip ospf interface brief command to display a summary of OSPF-enabled interfaces. R1# show ip ospf interface brief Interface PID Area IP Address/Mask ost State Nbrs F/ Se0/0/ /30 64 P2P 1/1 Se0/0/ /30 64 P2P 1/1 Gi0/ /24 1 DR 0/0 b. For a more detailed list of every OSPF-enabled interface, issue the show ip ospf interface command. R1# show ip ospf interface Serial0/0/1 is up, line protocol is up Internet Address /30, Area 0, Attached via Network Statement Process ID 1, Router ID , Network Type POINT_TO_POINT, ost: 64 Topology-MTID ost Disabled Shutdown Topology Name 0 64 no no Base Transmit Delay is 1 sec, State POINT_TO_POINT Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:01 Supports Link-local Signaling (LLS) isco NSF helper support enabled IETF NSF helper support enabled Index 3/3, flood queue length 0 Next 0x0(0)/0x0(0) 2013 isco and/or its affiliates. All rights reserved. This document is isco Public. Page 6 of 29

7 Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor ount is 1, Adjacent neighbor count is 1 Adjacent with neighbor Suppress hello for 0 neighbor(s) Serial0/0/0 is up, line protocol is up Internet Address /30, Area 0, Attached via Network Statement Process ID 1, Router ID , Network Type POINT_TO_POINT, ost: 64 Topology-MTID ost Disabled Shutdown Topology Name 0 64 no no Base Transmit Delay is 1 sec, State POINT_TO_POINT Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 Supports Link-local Signaling (LLS) isco NSF helper support enabled IETF NSF helper support enabled Index 2/2, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor ount is 1, Adjacent neighbor count is 1 Adjacent with neighbor Suppress hello for 0 neighbor(s) GigabitEthernet0/0 is up, line protocol is up Internet Address /24, Area 0, Attached via Network Statement Process ID 1, Router ID , Network Type BROADAST, ost: 1 Topology-MTID ost Disabled Shutdown Topology Name 0 1 no no Base Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) , Interface address No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:01 Supports Link-local Signaling (LLS) isco NSF helper support enabled IETF NSF helper support enabled Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 0 Last flood scan time is 0 msec, maximum is 0 msec Neighbor ount is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) Step 7: Verify end-to-end connectivity. Each P should be able to ping the other Ps in the topology. Verify and troubleshoot if necessary. Note: It may be necessary to disable the P firewall to ping between Ps isco and/or its affiliates. All rights reserved. This document is isco Public. Page 7 of 29

8 Part 3: hange Router ID Assignments The OSPF router ID is used to uniquely identify the router in the OSPF routing domain. isco routers derive the router ID in one of three ways and with the following precedence: 1) IP address configured with the OSPF router-id command, if present 2) Highest IP address of any of the router s loopback addresses, if present 3) Highest active IP address on any of the router s physical interfaces Because no router IDs or loopback interfaces have been configured on the three routers, the router ID for each router is determined by the highest IP address of any active interface. In Part 3, you will change the OSPF router ID assignment using loopback addresses. You will also use the router-id command to change the router ID. Step 1: hange router IDs using loopback addresses. a. Assign an IP address to loopback 0 on R1. R1(config)# interface lo0 R1(config-if)# ip address R1(config-if)# end b. Assign IP addresses to Loopback 0 on R2 and R3. Use IP address /32 for R2 and /32 for R3. c. Save the running configuration to the startup configuration on all three routers. d. You must reload the routers in order to reset the router ID to the loopback address. Issue the reload command on all three routers. Press Enter to confirm the reload. Instructor Note: The clear ip ospf process command does not reset the router IDs with the loopback address. Reloading the router will reset the router ID to the loopback address. e. After the router completes the reload process, issue the show ip protocols command to view the new router ID. R1# show ip protocols *** IP Routing is NSF aware *** Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: area area area 0 Routing Information Sources: Gateway Distance Last Update :01: :01:14 Distance: (default is 110) f. Issue the show ip ospf neighbor command to display the router ID changes for the neighboring routers isco and/or its affiliates. All rights reserved. This document is isco Public. Page 8 of 29

9 R1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface FULL/ - 00:00: Serial0/0/ FULL/ - 00:00: Serial0/0/0 R1# Step 2: hange the router ID on R1 using the router-id command. The preferred method for setting the router ID is with the router-id command. a. Issue the router-id command on R1 to reassign the router ID. Notice the informational message that appears when issuing the router-id command. R1(config)# router ospf 1 R1(config-router)# router-id Reload or use "clear ip ospf process" command, for this to take effect R1(config)# end b. You will receive an informational message telling you that you must either reload the router or use the clear ip ospf process command for the change to take effect. Issue the clear ip ospf process command on all three routers. Type yes to reply to the reset verification message, and press ENTER. c. Set the router ID for R2 to and the router ID for R3 to Then use clear ip ospf process command to reset ospf routing process. d. Issue the show ip protocols command to verify that the router ID changed on R1. R1# show ip protocols *** IP Routing is NSF aware *** Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: area area area 0 Passive Interface(s): GigabitEthernet0/1 Routing Information Sources: Gateway Distance Last Update :00: :00: :00: :00:41 Distance: (default is 110) e. Issue the show ip ospf neighbor command on R1 to verify that new router ID for R2 and R3 is listed. R1# show ip ospf neighbor 2013 isco and/or its affiliates. All rights reserved. This document is isco Public. Page 9 of 29

10 Neighbor ID Pri State Dead Time Address Interface FULL/ - 00:00: Serial0/0/ FULL/ - 00:00: Serial0/0/0 Part 4: onfigure OSPF Passive Interfaces The passive-interface command prevents routing updates from being sent through the specified router interface. This is commonly done to reduce traffic on the LANs as they do not need to receive dynamic routing protocol communication. In Part 4, you will use the passive-interface command to configure a single interface as passive. You will also configure OSPF so that all interfaces on the router are passive by default, and then enable OSPF routing advertisements on selected interfaces. Step 1: onfigure a passive interface. a. Issue the show ip ospf interface g0/0 command on R1. Notice the timer indicating when the next Hello packet is expected. Hello packets are sent every 10 seconds and are used between OSPF routers to verify that their neighbors are up. R1# show ip ospf interface g0/0 GigabitEthernet0/0 is up, line protocol is up Internet Address /24, Area 0, Attached via Network Statement Process ID 1, Router ID , Network Type BROADAST, ost: 1 Topology-MTID ost Disabled Shutdown Topology Name 0 1 no no Base Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) , Interface address No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:02 Supports Link-local Signaling (LLS) isco NSF helper support enabled IETF NSF helper support enabled Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 0 Last flood scan time is 0 msec, maximum is 0 msec Neighbor ount is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) b. Issue the passive-interface command to change the G0/0 interface on R1 to passive. R1(config)# router ospf 1 R1(config-router)# passive-interface g0/0 c. Re-issue the show ip ospf interface g0/0 command to verify that G0/0 is now passive. R1# show ip ospf interface g0/0 GigabitEthernet0/0 is up, line protocol is up Internet Address /24, Area 0, Attached via Network Statement Process ID 1, Router ID , Network Type BROADAST, ost: 1 Topology-MTID ost Disabled Shutdown Topology Name 0 1 no no Base Transmit Delay is 1 sec, State DR, Priority isco and/or its affiliates. All rights reserved. This document is isco Public. Page 10 of 29

11 Designated Router (ID) , Interface address No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 No Hellos (Passive interface) Supports Linklocal Signaling (LLS) isco NSF helper support enabled IETF NSF helper support enabled Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 0, maximum is 0 Last flood scan time is 0 msec, maximum is 0 msec Neighbor ount is 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) d. Issue the show ip route command on R2 and R3 to verify that a route to the /24 network is still available. R2# show ip route odes: L - local, - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop override Gateway of last resort is not set O L O L /32 is subnetted, 1 subnets is directly connected, Loopback /24 [110/65] via , 00:58:32, Serial0/0/ /24 is variably subnetted, 2 subnets, 2 masks /24 is directly connected, GigabitEthernet0/ /32 is directly connected, GigabitEthernet0/ /24 [110/65] via , 00:58:19, Serial0/0/ /24 is variably subnetted, 2 subnets, 2 masks /30 is directly connected, Serial0/0/ /32 is directly connected, Serial0/0/ /30 is subnetted, 1 subnets O [110/128] via , 00:58:19, Serial0/0/1 [110/128] via , 2013 isco and/or its affiliates. All rights reserved. This document is isco Public. Page 11 of 29

12 L 00:58:32, Serial0/0/ /24 is variably subnetted, 2 subnets, 2 masks /30 is directly connected, Serial0/0/ /32 is directly connected, Serial0/0/ isco and/or its affiliates. All rights reserved. This document is isco Public. Page 12 of 29